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631.
632.
T酸一次洗水初步处理的研究 总被引:4,自引:0,他引:4
采用重氮化-偶合-混凝沉淀和重氮化-混凝沉淀两种方法对T酸一次洗水的初步处理进步了研究。T酸一次洗水经两种方法处理后,COD去除率分别为61.3%、50.5%,色度去除率分别为74.6%、71%。 相似文献
633.
为了探究火源功率和水幕线性喷水强度对烟气特征参数和水幕阻烟隔热能力的影响,以全尺寸隧道为研究对象,采用FDS数值模拟方法,还原验证了前人使用的小尺寸模型,研究了20组工况下烟气特征参数变化的规律。研究结果表明:根据相似性原理还原后的全尺寸模型在相同工况下的模拟结果与小尺寸实验基本一致;水幕系统降低遮光率的效果随线性喷水强度增加而增强,当线性喷水强度增至一定程度时,遮光率和隔热效率无明显变化;对于中、大型规模火灾,水幕有效作用时间出现减少的情况;火源功率为5,20,30 MW的小、中、大规模的隧道火灾,综合考虑经济性和水幕效果,建议分别选择水幕的线性喷水强度为8,14,16 L/(s瘙簚m)。 相似文献
634.
635.
Saeed Ghavidelfar Asaad Y. Shamseldin Bruce W. Melville 《Journal of Environmental Planning and Management》2017,60(10):1809-1824
Over recent decades Auckland, New Zealand, metropolitan area has vastly expanded as a result of rapid population growth and low-density housing developments. In order to manage the uncontrolled low-density urban sprawl, Auckland Council proposed a compact city model through promoting higher density housing developments. In order to understand the implications of this transition on future residential water demand, this study first evaluated water consumption in three major housing types in Auckland including single houses, low-rise and high-rise apartments. Using the geographic information system, the water consumption information, estimated from a large sample of 60,000 dwellings across Auckland, was subsequently integrated with the Proposed Auckland Unitary Plan outlining the future housing composition over different areas in Auckland. Through developing different growth scenarios, the study showed that the housing transition from single houses to more intensified multi-unit houses cannot considerably affect the average per capita water consumption in Auckland. 相似文献
636.
Does Including Soil Moisture Observations Improve Operational Streamflow Forecasts in Snow‐Dominated Watersheds? 下载免费PDF全文
Adrian A. Harpold Kent Sutcliffe Jordan Clayton Angus Goodbody Shareily Vazquez 《Journal of the American Water Resources Association》2017,53(1):179-196
Changing climate and growing water demand are increasing the need for robust streamflow forecasts. Historically, operational streamflow forecasts made by the Natural Resources Conservation Service have relied on precipitation and snow water equivalent observations from Snow Telemetry (SNOTEL) sites. We investigate whether also including SNOTEL soil moisture observations improve April‐July streamflow volume forecast accuracy at 0, 1, 2, and 3‐month lead times at 12 watersheds in Utah and California. We found statistically significant improvement in 0 and 3‐month lead time accuracy in 8 of 12 watersheds and 10 of 12 watersheds for 1 and 2‐month lead times. Surprisingly, these improvements were insensitive to soil moisture metrics derived from soil physical properties. Forecasts were made with volumetric water content (VWC) averaged from October 1 to the forecast date. By including VWC at the 0‐month lead time the forecasts explained 7.3% more variability and increased the streamflow volume accuracy by 8.4% on average compared to standard forecasts that already explained an average 77% of the variability. At 1 to 3‐month lead times, the inclusion of soil moisture explained 12.3‐26.3% more variability than the standard forecast on average. Our findings indicate including soil moisture observations increased statistical streamflow forecast accuracy and thus, could potentially improve water supply reliability in regions affected by changing snowpacks. 相似文献
637.
In California, the growing popularity of urban agriculture (UA) has unfolded against a backdrop of historic drought. While UA is often celebrated as an urban sustainability strategy, it must be able to persist during drought if it is to perform these functions. Using Santa Clara County – the geographic core of Silicon Valley – as a case study, we use interviews and surveys to explore the implications of drought for UA. We show how developing an understanding of water access for UA during a drought requires examining the social and institutional context of water management and use. In metropolitan California, the highly decentralised water supply system combined with the diverse institutional arrangements that support UA create an uneven landscape of water access. Consequently, the pressure to change water-consuming practices – that is, the stress that institutional drought responses place on different water users – is geographically and socially differentiated. Among UA water users, responses to drought have also varied, in part because the possibilities for change are constrained by the sociotechnical arrangements of UA sites and the different purposes of UA. 相似文献
638.
北京市水资源开发利用已经超过了水资源承载能力范围,由此引发的水资源短缺问题日益严重.对污水的综合利用进行研究可以达到持续利用水资源的目的,解决水资源短缺问题.以北京市2005-2012年污水排放量资料为基础,运用灰色系统模型,对工业、生活污水排放量及总污水排放量进行了预测,分析北京市污水排放量走势及存在的问题,提出未来北京市污水综合利用的对策措施. 相似文献
639.
640.
针对杭州西湖钱塘江引水低碳高氮的特点,提出以改性水草塘—复合垂直流人工湿地(IVCW)相耦合的生物—生态工艺进行引水处理,对该引水降氮示范工程的构建和运行效果进行了跟踪研究。结果表明,整个稳定运行期间(2012年7月19日至11月19日),耦合工艺对COD、TN、硝酸盐氮、TP的平均去除率分别为52.27%、52.49%、53.69%、52.79%,系统出水满足《地表水环境质量标准》(GB 3838—2002)Ⅳ标准;改性水草塘和IVCW单元作为耦合工艺的两个重要组成部分,在脱氮、除磷方面优势互补,从而共同保证出水水质的稳定;在改性水草塘单元,温度与COD的去除效果呈负相关关系,进水C/N与TN去除效果呈正相关关系;而在IVCW单元,温度与COD、TN的去除效果均呈线性正相关关系,进水C/N与两者的去除效果也呈正相关关系,且对COD的影响要大于对TN的影响。 相似文献